Answer:
With three eyes and as black as night I frequently knock down ten men with a single strike!
Use me if you really want to see inside someone
I am rarely touched but often held and if you are smart you'll use me well.
If a man carries my burden they will get crushed to death. Though not rich I leave silver in my track.
You write on me and secrets I can keep. In places never seen. I spin like a top. Though stiff as a board I'm often described like a mop.
When is it bad luck to see a black cat?